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18 Sound

18 Sound 18LW1400

18 Sound 18LW1400: 18″ subwoofer driver with ferrite motor, Fs 31 Hz and Qts 0.29 – the manufacturer gives 220 L as the enclosure volume.

Current · Last checked: 2026-09-28

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Schematic cross-section: 18″ driver with ferrite motor Side section: on the left the motor with a large ferrite ring magnet, pole piece and top plate with the air gap. The voice coil sits in the gap on its former, held by the spider. To the right the cone opens out with its dust cap, with the surround at the edge of the basket. The drawing shows the construction, not the dimensions of a particular model.
Schematic cross-section of a driver with a ferrite motor. The drawing shows the construction, not the dimensions of this model; the manufacturer has a product photo.

General data

Link to section “General data”
Type
Subwoofer driver
Nominal size
18″
Nominal impedance
8 Ω Manufacturer
Minimum impedance
6.4 Ω Manufacturer
Sensitivity
98 dB 2.83 V / 1 m Manufacturer
Frequency range
28 Hz – 2,500 Hz Manufacturer
Voice coil Ø
100 mm Manufacturer
Winding height
not available
Gap depth
not available
Flux density
not available
Magnet
ferrite
Weight
13.3 kg Manufacturer
Baffle cut-out Ø
416 mm Manufacturer
Overall diameter
462 mm Manufacturer
Mounting depth
215 mm Manufacturer
Displacement
not available
Recommended enclosure volume
220 – 220 L Manufacturer

Sensitivity is referenced to 2.83 V at 1 m, i.e. to 1 W only at exactly 8 Ω. The manufacturer does not state Cms; the value is left empty here.

On this model, programme power is only 1.5 dB above rated power handling and thus does not follow the 3 dB rule otherwise stated by 18 Sound.

What can this driver do?

Link to section “What can this driver do?”

Simulation from the datasheet values above. The suggestions are calculated, not stated by the manufacturer.

Bass reflex Sealed Calculated

The EBP is between 50 and 100 – by the rule of thumb, both a bass reflex and a sealed enclosure are possible. This is based on an EBP of 100.

Net volume
186 L
Tuning frequency
41 Hz
F3 (−3 dB)
39.4 Hz
F6 (−6 dB)
35.5 Hz
F10 (−10 dB)
31.4 Hz
Sensitivity (2.83 V / 1 m)
98.7 dB
Max. SPL at 39.4 Hz
125.7 dB
Max. SPL at 78.7 Hz
128 dB
Xmax limits below
84.9 Hz
Ports
1 × 315 mm
Port area for 17 m/s
734 cm²
Max. port velocity
16 m/s
Port length
51.4 cm
1020501002005001k708090100110120130140Frequency (Hz)Level (dB SPL)
  • at 1,000 W
  • Maximum SPL (limited by Xmax)
  • Power into 8 Ω (nominal impedance of the wiring).
  • Flattest alignment: lowest F3 without the response rising more than 0.25 dB above the passband level or dropping more than 0.5 dB at 2 × F3.
  • The 17 m/s limit (about 5 % of the speed of sound) is a common rule of thumb against port noise, not a standard. Rounded port ends allow higher values.
  • Lumped-element Thiele/Small model, Half space, 1 m, chamber losses QL 7, Le as a plain inductance, no room influence. At high levels (heating, non-linear Bl and Cms) real results are lower.

Open in the designer

Thiele-Small parameters

Link to section “Thiele-Small parameters”

Small-signal parameters as stated by the manufacturer. They change with temperature and level.

Fs
31 Hz
Re
5 Ω
Le
2.3 mH (at 1,000 Hz)
Qts
0.29
Qes
0.31
Qms
7.2
Vas
297 L
BL
24.7 T·m
Mms
190 g
Cms
not available
Sd
1,225 cm²
Xmax
9 mm
Xdamage
not available
Vd
not available
EBP
not available
Efficiency η₀
not available

Plausibility check

Link to section “Plausibility check”

We recalculate dependent values from the datasheet. We flag deviations above 3 %.

Recalculated parameters
CheckFormula DatasheetCalculatedResult
Qts from Qes and Qms Qts = Qes · Qms / (Qes + Qms) 0.29 0.297 consistent

Power handling

Link to section “Power handling”
  • Continuous power (standard not stated)1,000 W
  • Programme power1,400 W

Sources

Link to section “Sources”
  1. Tier A · primary source

    18 Sound 18LW1400 (8 Ω) – Product page with Thiele-Small parameters

    Eighteen Sound S.r.l. · accessed on 28 September 2026